scholarly journals The Influence of the Layer Arrangement on the Distortional Post-Buckling Behavior of Open Section Beams

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3002
Author(s):  
Tomasz Kubiak ◽  
Mariusz Urbaniak ◽  
Filip Kazmierczyk
Keyword(s):  
Cross Sections ◽  
Numerical Models ◽  
Experimental Tests ◽  
Distortional Buckling ◽  
Buckling Mode ◽  
Layer Arrangement ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Buckling Behavior ◽  
Post Buckling

The paper deals with the design of the stacking sequence of layers in the laminate beams with open-cross sections in order to create the desired behavior in the post-buckling range. Laminate beams with channel and lipped channel cross-sections made of glass fiber reinforced polymer (GFRP) laminate with different layer arrangements (symmetrical and nonsymmetrical) have been considered. In case of the nonsymmetrical stacking sequences, hygro-thermally curvature stable (HTCS) laminates have been taken into account. Pure bending was assumed as the type of load. In the case of beams with open cross-sections, this load type can cause the lateral-distortional buckling mode. A parametric study was performed to analyze the influence of layer arrangement on post-buckling behavior. The finite element method was used to developed numerical models and conduct simulations. Additionally, the experimental tests of the channel section beams were performed in order to validate the developed numerical models.

Behavior and Design of Web-Slotted Cold-Formed Channels Experiencing Local-Distortional-Global Interactive Buckling

2013 ◽  
Vol 351-352 ◽  
pp. 747-752
Author(s):  
Shuai Liu ◽  
Qi Jie Ma ◽  
Pei Jun Wang
Keyword(s):  
Effective Width ◽  
The Finite Element Method ◽  
Distortional Buckling ◽  
Buckling Mode ◽  
Geometric Imperfection ◽  
Interactive Behavior ◽  
Buckling Behavior ◽  
Initial Geometric Imperfection ◽  
Interactive Buckling ◽  
Shed Light

This article aims to shed light on the nonlinear local-distortional-global interactive behavior of web-slotted channel columns by use of the finite element method. The effects of three kinds of initial geometric imperfection based on different distortional buckling mode were evaluated. It indicates that different distortional buckling mode does little difference on the nonlinear interactive buckling behavior of web-slotted channels. Based on the extensive parametric study, some modifications were made to the traditional Effective Width Method for the practical design of web-slotted channel columns undergoing local-distortional-global interactive buckling.

scholarly journals Buckling Analysis of Pultruded Glass Fiber Reinforced Polymer (GFRP) Angle Sections

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2532
Author(s):  
Rahima Shabeen Sirajudeen ◽  
Rajesh Sekar
Keyword(s):  
Glass Fiber ◽  
Slenderness Ratio ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced Polymers ◽  
Fe Model ◽  
Fiber Reinforced ◽  
Glass Fiber Reinforced Polymer ◽  
Buckling Mode ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced

Glass fiber reinforced polymers (GFRP), with their advantage of corrosion resistance, have potential to be used as structural members in civil engineering constructions. Pultruded GFRP angle section trusses could be used instead of steel sections in remote areas and in areas prone to corrosion. The objective of this paper is to study the strength of GFRP angle sections under concentric axial load. Glass fiber reinforced polymer (GFRP) made of E-glass and Isophthalic polyester resin and manufactured by pultrusion process was used for the experimental study. Two GFRP angle sections of size 50 × 50 × 6 mm and 50 × 50 × 4 mm and lengths 500 mm, 750 mm, and 1000 mm were chosen for the study. Further, finite experimental element analysis of the GFRP angle sections was done using ANSYS software and validated with the experimental results. The validated FE model was used for parametric studies varying the slenderness ratio and flange width to thickness ratio (b/t) ratio. It was observed that length of the specimen and thickness influenced the buckling load and buckling mode. An increase in b/t ratio from 8.3 to 12.5 decreases the load carrying capacity by almost 60% at a slenderness ratio of 50.

LOCAL/DISTORTIONAL/GLOBAL MODE INTERACTION IN SIMPLY SUPPORTED COLD-FORMED STEEL LIPPED CHANNEL COLUMNS

2011 ◽  
Vol 11 (05) ◽  
pp. 877-902 ◽  
Author(s):  
P. B. DINIS ◽  
D. CAMOTIM
Keyword(s):  
Shell Element ◽  
Mode Interaction ◽  
Buckling Mode ◽  
Global Mode ◽  
Simply Supported ◽  
Elastic Plastic ◽  
Buckling Behavior ◽  
Geometrical Imperfections ◽  
Post Buckling ◽  
Cold Formed Steel

This paper reports the results of a numerical investigation concerning the elastic and elastic-plastic post-buckling behavior of cold-formed steel-lipped channel columns affected by local/distortional/global (flexural-torsional) buckling mode interaction. The results presented and discussed are obtained by means of analyses performed in the code ABAQUS and adopting column discretizations into fine four-node isoparametric shell element meshes. The columns analysed (i) are simply supported (locally/globally pinned end sections with free warping), (ii) have cross-section dimensions and lengths ensuring equal local, distortional, and global (flexural-torsional) critical buckling loads, thus maximizing the mode interaction phenomenon under scrutiny, and (iii) contain critical-mode initial geometrical imperfections exhibiting different configurations, all corresponding to linear combination of the three "competing" critical buckling modes. After briefly addressing the lipped channel column "pure" global post-buckling behavior, one presents and discusses in detail numerical results concerning the post-buckling behavior of similar columns experiencing strong local/distortional/global mode interaction effects. These results consist of (i) elastic (mostly) and elastic-plastic equilibrium paths, (ii) curves and figures providing the evolution of the deformed configurations of several columns (expressed as linear combinations of their local, distortional, and global components) and, for the elastic-plastic columns, (iii) figures enabling a clear visualization of (iii1) the location and growth of the plastic strains, and (iii2) the characteristics of the failure mechanisms more often detected in this work.

scholarly journals Numerical Simulation of Buckling and Post-Buckling Behavior of a Central Notched Thin Aluminum Foil with Nonlinearity in Consideration

Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 582 ◽  
Author(s):  
Mahdieh Shahmardani ◽  
Per Ståhle ◽  
Md Shafiqul Islam ◽  
Sharon Kao-Walter
Keyword(s):  
Mode Shape ◽  
Tensile Loading ◽  
Width Ratio ◽  
Plastic Behavior ◽  
Yield Limit ◽  
Buckling Mode ◽  
Buckling Stress ◽  
Buckling Behavior ◽  
Sheet Width ◽  
Post Buckling

In thin notched sheets under tensile loading, wrinkling appears on the sheet surface, specifically around the cracked area. This is due to local buckling and compression stresses near the crack surfaces. This study aims to numerically study the buckling behavior of a thin sheet with a central crack under tension. A numerical model of a notched sheet under tensile loading is developed using the finite element method, which considers both material and geometrical nonlinearity. To overcome the convergence problem caused by the small thickness-to-length/width ratio and to stimulate the buckling, an imperfection is defined as a small perturbation in the numerical model. Both elastic and elasto-plastic behavior are applied, and the influence of them is studied on the critical buckling stress and the post-buckling behavior of the notched sheet. Numerical results for both elastic and elasto-plastic behavior reflect that very small perturbations need more energy for the activation of buckling mode, and a higher buckling mode is predominant. The influences of different parameters, including Poisson’s ratio, yield limit, crack length-to-sheet-width ratio, and the sheet aspect ratio are also evaluated with a focus on the critical buckling stress and the buckling mode shape. With increase in Poisson’s ratio. First, the critical buckling stress reduces and then remains constant. A higher yield limit results in increases in the critical buckling stress, and no change in the buckling mode shape while adopting various crack length-to-sheet-width ratios, and the sheet aspect ratio changes the buckling mode shape.

Onset and Post Buckling of Pipe-in-Pipe’s Helical Buckling Using Improved Energy Method

2018 ◽  
Author(s):  
Lixin Gong
Keyword(s):  
Potential Energy ◽  
Energy Method ◽  
Normal Force ◽  
Horizontal Wells ◽  
Energy Methods ◽  
Buckling Mode ◽  
Buckling Behavior ◽  
Post Buckling ◽  
Helical Buckling ◽  
Remarkable Agreement

The purpose of this paper is to present theoretical solutions based on an improved energy method for predicting the helical buckling (HB) behavior of pipes in vertical, inclined, and horizontal wells. The energy method has been applied to solve the pipe-in-pipe’s (PIP) helical buckling behavior since Lubinski, et al [2] in the 1950’s. However, in the preceding studies, the energy methods are not yet completely correct because the pipe’s potential energy of the distributed contact normal force induced by the helical buckling was considered to be negligible. This deficiency caused improper deductive procedures. In this paper, the energy method is improved by adding the term of the potential energy of the distributed contact normal force. With this improvement, not only can the PIP’s critical helical buckling forces be successfully derived, but it also provides a deeper insight on the PIP’s helical buckling onset, as well as the post helical buckling behavior. For inclined and horizontal wells, equations are provided to determine the critical forces required to initiate the helical buckling mode for both “long” and “short” pipes. In addition, the post buckling behavior is also described, and a new concept of helical buckling zone (HBZ) for “short” pipes is introduced based on the force-pitch plots as an area in-between the helical buckling’s onset curve and the classical Lubinski curve. Finite element ABAQUS models have also been utilized to confirm the analysis using the improved energy method. And the ABAQUS results show remarkable agreement with the theoretical solutions.

Effects of symmetric imperfections on the behavior of bistable struts

2016 ◽  
Vol 22 (12) ◽  
pp. 2240-2252 ◽  
Author(s):  
Jianguo Cai ◽  
Xiaowei Deng ◽  
Jian Feng
Keyword(s):  
Virtual Work ◽  
Variable Geometry ◽  
Equilibrium Equations ◽  
Buckling Mode ◽  
Concentrated Load ◽  
Virtual Work Principle ◽  
Shallow Arches ◽  
Buckling Behavior ◽  
Nonlinear Equilibrium ◽  
Post Buckling

The behavior of a bistable strut for variable geometry structures was investigated in this paper. A three-hinged arch subjected to a central concentrated load was used to study the effect of symmetric imperfections on the behavior of the bistable strut. Based on a nonlinear strain–displacement relationship, the virtual work principle was adopted to establish both the pre-buckling and buckling nonlinear equilibrium equations for the symmetric snap-through buckling mode. Then the critical load for symmetric snap-through buckling was obtained. The results show that the axial force is in compression before the arch is buckled, but it becomes in tension after buckling. Thus, the previous formulas cannot be used for the analysis of post-buckling behavior of three-hinged shallow arches. Then, the principle of virtual work was also used to establish the post-buckling equilibrium equations of the arch in the horizontal and vertical directions as well as the static boundary conditions, which are very important for bistable struts.

scholarly journals Global-distortional buckling mode influence on post-buckling behaviour of lip-channel beams

2020 ◽  
Vol 184 ◽  
pp. 105723 ◽  
Author(s):  
Zbigniew Kolakowski ◽  
Tomasz Kubiak ◽  
Monika Zaczynska ◽  
Filip Kazmierczyk
Keyword(s):  
Distortional Buckling ◽  
Buckling Mode ◽  
Post Buckling

Experimental and numerical assessment of CHS-RHS T-joints with chords subjected to axial tensile forces

2021 ◽  
pp. 136943322110032
Author(s):  
João Batista da Silva Neto ◽  
Gabriel Vieira Nunes ◽  
Arlene Maria Cunha Sarmanho ◽  
Daniel José Rocha Pereira ◽  
Messias Júnio Lopes Guerra ◽  
...  
Keyword(s):  
Cross Sections ◽  
Numerical Models ◽  
Experimental Tests ◽  
T Joints ◽  
Axial Tensile ◽  
Joint Resistance ◽  
Tensile Forces ◽  
Steel Sections ◽  
Axially Loaded ◽  
New Equation

Hollow steel sections are widely used in the construction industry due to their mechanical properties. Joints used in these structures are the subject of research because of their singular and critical behavior. Joints containing chords with more slender cross-sections and axially loaded are still a challenge for design, especially in joints with circular hollow sections (CHS) in the braces and rectangular hollow sections (RHS) in the chords. In this context, this work aimed to study joints formed by a combination of CHS braces subjected to compression loads and RHS chords axially loaded with tension, welded as T-joints. Experimental tests, a numerical model using finite elements, and a parametric analysis were developed. A new equation for the chord stress function was proposed, including joints containing chords with semi-compact sections in tension. The joint resistance values obtained through the numerical models were compared with the equations from ISO 14346:2013 and with the proposed equation. It was observed that, for the numerical models with geometric properties inside the normative validity ranges of ISO 14346:2013, the mean rate of analytical by numerical joint resistance results was equal to 68%, using either the normative or the proposed equation. In the same way, for models outside the current validity ranges, either the proposed equation or the modified equation from ISO 14346:2013 could be used to design CHS-RHS T-joints with the geometric and material properties analyzed.

Post-Buckling Behavior of Pressurized Long Circular Cylindrical Shells

1986 ◽  
Vol 30 (03) ◽  
pp. 172-176
Author(s):  
Charles W. Bert ◽  
Victor Birman
Keyword(s):  
Differential Equation ◽  
Cross Sections ◽  
Cylindrical Shells ◽  
Bending Moment ◽  
Global Behavior ◽  
Arbitrary Boundary ◽  
Buckling Behavior ◽  
Post Buckling ◽  
Circular Cylindrical Shells ◽  
The Relationship

The problem of post-buckling behavior of long, vertical, circular cylindrical shells loaded by nonuniform pressure, tension, and their own weight is formulated in this paper. The global behavior is considered by assuming that local deformations do not influence the solution. The nonlinear effect is due to the softening of the relationship between the bending moment and curvature due to the effect of the flattening of the shell cross sections. The nonlinear differential equation obtained in this paper describes the post-buckling behavior of a shell with linearly distributed pressure along the axis and arbitrary boundary conditions. In the general case this problem must be solved numerically. An analytical solution is presented for a particular case of a shell loaded by a uniform external or internal pressure.

Investigation on crushing behavior of laminated conical absorbers with different arrangements under axial loading

2019 ◽  
Vol 234 (3) ◽  
pp. 394-407
Author(s):  
Ali Akhavan Attar ◽  
Mahdi Kazemi
Keyword(s):  
Cross Sections ◽  
Peak Load ◽  
Axial Loading ◽  
Numerical Data ◽  
Experimental Tests ◽  
Finite Element Method Simulation ◽  
Absorption Capacity ◽  
Layer Arrangement ◽  
Number Of Layers ◽  
Crushing Behavior

Abstracts In this paper, the crushing properties of conical tubes made of stainless steel 430 have been investigated with different arrangements under quasi-static axial load both experimentally and numerically. For numerical investigation, nonlinear finite element method simulation is conducted using LS-Dyna software. In the experimental tests, the specimens with the height, major diameter, minor diameter and thickness of 150, 70, 50 and 1 mm are considered, respectively. Different combinations of layers are prepared using different cross-sections. A total of seven different arrangements have been designed in three distinct groups with constant mass and the crushing behavior has been extracted for them. To ensure the validity of the simulation results, several specimens which have the thickness of 1 mm have been tested experimentally. Comparing the results indicates the consistency of the experimental and numerical data. According to the obtained results, it is observed that with increasing the number of layers, the energy absorption capacity is increased; moreover, the peak load is increased by 75.2%. In fact, with increasing the number of layers, increasing trend is observed in peak load, and contrary to the initial expectations, this trend is not linear. It is also observed that by changing the layer arrangement and the layer number, the mean crushing force can increase approximately three times.

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